Many food containers are known which are preassembled and preglued to a defined three-dimensional shape. Such containers, however, are bulky for both shipment and storage, and thus are not desired in many use applications, such as for carry-out pizza.
Various types of foldable blanks are also known which are used to create a box or other suitable support for packaging and carrying food products such as pizza. Prepared ready-to-eat pizza and other food items for take-out or delivery are often packaged in a square box formed from such a foldable blank, which boxes typically have an attached openable lid or cover. Use of flat blanks which are easily assembled without glue or adhesive, which can be easily and compactly stored, and which can be easily assembled at the use site, is thus highly preferred in many use situations.
Many take-out or pizza establishments pre-fold or set up food boxes prior to usage in order to save time during busy periods. As a result, a typical pizzeria can have a large number of set up boxes within the store, which consumes considerable storage space. As such, boxes which are capable of being nested one within the other and stacked are known, such as those disclosed in U.S. Pat. Nos. 1,725,524 and 5,713,509. For example, the box illustrated in U.S. Pat. No. 1,725,524 has side walls which, when assembled, have a tapered configuration for permitting vertical stacking of the boxes within one another. These known arrangements, however, either do not possess a structure which provides the necessary rigidity and structural integrity when assembled and subsequently transported and/or possess a structure more complex and hence more expensive than desired.
More specifically, many food containers which are formed and folded from flat blanks utilize blanks which are of thin paperboard and thus are quite flexible, and hence can be partially prefolded and still partially nest when stacked due to the flexibility of the board. These containers, however, are relatively weak, possess less than desired rigidity, and do not possess desired thermal or moisture absorbing properties for optimum use with hot food products. Because of these disadvantages, many food containers and particularly pizza boxes are formed and folded from flat blanks of corrugated cardboard, typically double faced corrugated cardboard, because of the strength, rigidity and other desired physical properties thereof. The stiffness of these corrugated blanks, however, has prevented most such containers from being nested in an assembled condition, thereby requiring a large storage space for the preassembled containers.
Accordingly, it is an object of the invention to provide an improved food container for supporting a food product such as pizza, which food container is formed by being folded from a corrugated cardboard flat blank and when partially folded or assembled is capable of being nested so as to conserve space during storage thereof, and which container is stable and has improved rigidity to allow for safe handling and transport of the food product therein.
More specifically, the improved food container, in accordance with one aspect of the invention, includes upper and lower portions joined to one another such that the upper portion is pivotable away from and toward the lower portion to respectively define open and closed configurations of the container. The lower portion includes a generally horizontally enlarged and planar bottom wall having a pair of generally parallel first side edges and a pair of second side edges extending generally perpendicularly relative to the first side edges. First and second elongate side walls are integrally joined to the bottom wall and fold upwardly about the first side edges, and angle outwardly relative to the bottom wall. A front flap extends outwardly from a front end of each side wall, and a rear flap extends outwardly from a rear end of each side wall. Each front and rear flap is folded about respective front and rear fold lines which form an angle greater than 90.degree. relative to a corresponding one of the first side edges to define front and rear corners of the bottom portion. A rear slot is disposed adjacent each rear corner, and a front slot is disposed adjacent each front corner. The lower portion includes front and rear side walls which are integrally joined to the bottom wall and fold upwardly about the second side edges. The front and rear side walls are angled outwardly relative to the bottom wall. The upper portion includes a generally planar top wall having a pair of generally parallel first side edges and a pair of generally parallel second side edges extending generally perpendicularly relative to the first top wall side edges. Upper portion also includes first and second elongate side walls integrally joined to the top wall and folded therefrom about fold lines which extend along the top wall first side edges. Each first and second top wall side wall has a locking tab which extends outwardly from an end thereof adjacent the rear side wall, each for engagement within a corresponding one of the rear slots in the closed configuration of the container. The top wall is integrally joined to the rear side wall and pivotable with respect thereto. Upper portion further includes a third elongate side wall integrally joined to the top wall and folded therefrom about a fold line which extends along the other of the top wall second side edges. The third side wall has a pair of locking tabs extending outwardly from opposite ends thereof, each for engagement within a corresponding one of the front slots.
Another aspect of the invention resides in a food container having upper and lower portions whereby the lower portion includes a planar bottom wall having a pair of generally parallel first side edges and a pair of generally parallel second side edges extending generally perpendicular relative to the first side edges, and first and second elongate side walls integrally joined to the bottom wall and folded upwardly therefrom about fold lines which extend along the first side edges. The lower portion also includes front and rear side walls integrally joined to the bottom wall and folded upwardly therefrom about fold lines which extend along a respective one of the second side edges. The first and second side walls and also the front and rear side walls are oriented at an interior angle greater than 90.degree. with respect to the bottom wall to enable vertical stacking of a plurality of assembled but open containers one atop the other. Further, opposite ends of the rear side wall, along with adjacent rear ends of each of the first and second side walls form a pair of rear corners of the container, and opposite ends of the front side wall along with adjacent front ends of the first and second side walls form a pair of front corners of the container. The lower portion additionally includes a pair of upwardly opening slots, each disposed adjacent a respective one of the front corners. The upper portion of the container includes a generally planar top wall having a first pair of parallel side edges and a second pair of generally parallel side edges extending generally perpendicularly relative to the first pair of top wall side edges. The top wall is integrally joined to the rear side wall about a fold line which extends along one of the first top wall side edges, and an elongate side wall is integrally joined to the top wall and folded therefrom about a fold line which extends along the other of the first top wall side edges. The top wall side wall has a pair of locking tabs extending outwardly from opposite ends thereof each for engagement within one of the slots in the closed configuration of the container.